Risk assessment for dam failure using probability approach

Experience has shown that a dam can fail in many different ways and that different consequences of failure are associated with the particular failure modes. These consequences could be natural e.g earthquakes, floods, landslides or human made failure due to under/over judgements in investigation, design, construction, operations, maintenance etc. Thus, calculating and summing the probabilities of failure due to possible modes to determine the total risk as a system is an essential component of risk assessment. This has been achieved using event trees method to calculate the probability of failure of a dam together with assumed values for annual exceedence probabilities of the initiating events like flood and earthquake. The probabilities of failure for various components of New Victoria Dam was analysed using probability distribution and with subject to extreme values of standard deviations and the failure of the components upon which that dam as a system depend for Its reliability. Rational analytical models to analyse reliability using conditional probability of failure of various structures or part of structures, given a particular analysis, are essential to attain the precise estimates for the probability of failure.